In a related-art semiconductor laser apparatus, the following technology for improving the brightness of a semiconductor laser is known. Divergence angles of beams emitted from light emitting points of a semiconductor laser bar are corrected, and the beams are rotated and then focused on a wavelength dispersion optical element with use of a lens. Wavelength dispersibility of the wavelength dispersion optical element is utilized to overlap the beams emitted from the light emitting points, and a partially transmissive mirror is arranged for the overlapped beams to form an external cavity (see, for example, Patent Literature 1).